1. Technical Field
The present invention relates to switched communications networks providing voice mail services, more particularly to a system and method for notifying mobile wireless subscribers of voice mail messages stored on separate voice mail systems of public or private telephone networks.
2. Background Art
Voice mail has become commonplace not only in business usage but also on an individual telephone service subscriber basis through service from a central office. A voice mail system is a specialized computer that stores messages in digital form on a disk. The voice is generally digitized, usually at a much slower rate than the 64 Kb/s signal the central office uses in its switching network. The digitized voice is compressed and stored on a hard disk that maintains the voice mail operating system, system prompts, and greetings, and the messages themselves. A processor controls the compressing, storing, retrieving, forwarding and purging of files. A comprehensive review of exemplary voice mail systems and voice messaging systems is disclosed in U.S. Pat. No. 5,631,948 to Bartholomew et al., the disclosure of which is incorporated in its entirety herein by reference. While these systems effectively meet the general needs for messaging services, options for notification to subscribers of their waiting messages are not always adequate.
FIG. 1 is a block diagram illustrating an exemplary voice mail implementing communication system, corresponding to FIG. 5 of the above-incorporated Bartholomew et al. patent. As shown in FIG. 1, at least one switching system 10 is connected to a centralized message service voice mail 20. The switching system 10 may be a local or xe2x80x9cend officexe2x80x9d type telephone central office switch, such as a 1AESS or 5ESS switch sold by American Telephone and Telegraph.
Structurally, the switching system 10 is a standard central office telephone switch. Each subscriber has at least one piece of customer premises equipment, illustrated as telephone station sets 31 to 33. Local telephone lines 35 to 37 serve as communication links between each of the telephone station sets 31 to 33 and the end office switching system 10.
The centralized message service or voice mail system in FIG. 1 comprises voice messaging equipment such as a voice mail system 20. Although referred to as xe2x80x9cvoicexe2x80x9d messaging equipment, equipment 20 may have the capability of storing messages of a variety of different types as well as voice messages. Message service systems having the capability to store messages in a variety of audible, data and image formats are known, see e.g. U.S. Pat. No. 5,193,110 to Jones et al., U.S. Pat. No. 5,008,926 to Misholi and U.S. Pat. No. 4,652,700 to Matthews et al.
The illustrated voice mail system 20 includes a digital switching system (DSS) 21, a master control unit (MCU) 23, a number of voice processing units (VPU""s) 25 and a master interface unit (MIU) or concentrator 27. The master control unit (MCU) 23 of the voice mail system 20 is a personal computer type device programmed to control overall operations of the system 20.
An ETHERNET (IEEE 802.3) type digital network 29 carries data signals between the MCU 23 and the voice processing units 25, as well as between the various voice processing units 25. The system 20 further includes T1 type digitized audio links 28 between the DSS switch 21 and each of the voice processing units 25.
The voice mail system 20 connects to the switching system 10 via a number of simplified message desk interface (SMDI) type data lines 41 that connect between one or more data units (not shown) in the end office switching system 10 and the MIU 27. The MIU 27 is a data concentrator which effectively provides a single connection of as many as thirty-two SMDI lines into the MCU 23 of the voice mail system.
The voice mail system 20 also connects to the end office switching system 10 via a number of voice lines 43 which form a multi-line hunt group (MLHG) between the switching system 10 and the DSS switch 21, each carrying 24 voice channels in digital time division multiplexed format.
When the end office switching system 10 forwards a call to the voice mail system 20, the switching system 10 will also provide various forwarding data relating to the forwarded call via one of the SMDI links 41 and the MIU 27, for example which line of the multi-line hunt group 43 that the new call will come in on, the called telephone number and the telephone number of the caller (i.e., calling party). The master control unit 23 uses the multi-line hunt group line information and the subscriber""s directory number to internally route the forwarded call though DSS switch 21 and one of the internal T1 links 28 to an available voice processing unit 25 and identifies the relevant subscriber to that voice processing unit via the Ethernet 25.
Hence, the voice mail messaging system 20 is configured for receiving forwarded telephone calls for a called party (e.g., subscriber 31) having subscriber profile information stored in the end office switching system 10. Hence, upon detecting a no answer/busy condition on the corresponding line 37, the end office switching system can forward the incoming call to the MLHG 43 and supply the appropriate information associated with the called party across the SMDI link 41 to internally route the forwarded call to the assigned voice processing unit 25 and to identify the relevant subscriber to the voice processing unit 25.
Each time that the voice mail system 20 stores a new message in a particular subscriber""s mailbox, the system 20 will provide a message waiting indication to the end office switching system 10 via the MIU 27 and one of the SMDI links 41. In response to the message waiting signal, the end office switching system 10 sets an appropriate flag in its internal memory associated with that subscriber""s line. If the flag is already set, e.g. due to recording of an earlier message, the switching system 10 essentially ignores the latest signal and maintains the on state of the message waiting flag. Subsequently, when someone returns to the subscriber""s premises and attempts to initiate a call, the end office switching system 10 will provide a distinctive dial tone, typically an interrupted or xe2x80x9cstutterxe2x80x9d dial tone, to signify that the subscriber""s mailbox contains a new message. The end office switching system 20 may provide a variety of other message waiting indicators, such as a short ring when a person hangs up the telephone to terminate a call at the subscriber""s premises.
Similar types of voice messaging systems are found in private networks, such as corporate networks having a private branch exchange. In such instances, a private branch exchange (PBX) processes an incoming call by ringing a telephone having a prescribed extension. If the PBX detects a no answer/busy condition at the extension, the PBX transfers the incoming call to a voice mail platform along with the called party information, enabling the voice mail platform to play a personalized announcement for recording a message.
Once the message is recorded, the voice mail platform sends a message waiting indicator to the PBX specifying the extension has a message. Depending upon the implementation, the PBX will notify the subscriber at the extension of the existence of a message by setting a visual message waiting indicator on the telephone at the subscriber""s premises, for example an LED or a flashing LCD symbol, or by generating an audible message waiting indicator such as an interrupted or xe2x80x9cstutterxe2x80x9d dial tone output by the headset upon detecting an off-hook condition on the extension.
Hence, both public and private telephone networks provide a message waiting indicator at the customer premises corresponding to the dialed number served by the voice mail system. The message waiting indicator may be either a visual indicator physically located on the telephone at the customer premises, or an audible indicator from the handset such as an interrupted dial tone that is generated upon detection of an off-hook condition at the customer premises. Such an arrangement is ineffective, however, in the case where a subscriber is away from the customer premises, i.e., is out of visual range of the telephone. In particular, the visual notification on the telephone can only be detected by the subscriber upon direct visual inspection of the specific telephone. In addition, the audible notification may not be detected until the subscriber actually returns and picks up the handset to place a telephone call.
Hence, a subscriber that is away from the telephone will be unaware of any new messages stored on the voicemail system. This can be a substantial annoyance for a subscriber who cannot always be present at his or her office, but who is still within the same building. The problem is of additional concern to business travelers, who must constantly dial into the voice mail system to check for any new messages, else risk missing an important voice mail message.
Paging systems enable mobile subscribers to be paged by a calling party accessing the paging network. Exemplary paging systems include U.S. Pat. No. 5,144,648 to Bhagat et al. and U.S. Pat. No. 4,885,577 to Nelson, the disclosures of which are incorporated in their entirety herein by reference.
Bhagat et al. discloses a National Satellite Paging System (NSP) capable of processing both numeric and alphanumeric pages and recording voice messages. A calling party accesses the paging system by calling prescribed telephone numbers for a specific paging format. For example a calling party may call a SKYPAGER service for numeric and alphanumeric pages, and a SKYTALK service for recording voice messages. Upon connection with the SKYPAGER or SKYTALK service, the calling party is prompted to enter the personal identification number (PIN) for the mobile subscriber. In response to obtaining the PIN from the calling party, the paging system obtains the subscriber profile information for the mobile subscriber.
If the calling party wishes to record a voice message, the calling party is transferred to a voice mailbox unit that records the message. The voice mailbox unit then establishes a communication link with a central computer configured for processing pages. The voice mailbox informs the central computer in accordance with a Telocator Network Paging Protocol (TNpp) that the mobile subscriber corresponding to the PIN entered by the calling party has a stored message. The central computer updates the subscriber""s profile and transmits a page to the mobile subscriber instructing the subscriber to call into SKYTALK and retrieve the message.
The above-described paging systems, however, require that the calling party dial a second communications system that is separate from the original voicemail system if the calling party cannot reach the mobile subscriber at the original customer premises. In other words, a calling party calling a subscriber""s office telephone number may reach a voicemail prompt instructing the calling party to either leave a message or page the subscriber at a second pager number. The calling party would then need to disconnect, initiate a second telephone call by dialing the second pager number to access the paging system, and then page the mobile subscriber. Hence, the calling party needs to make two separate phone calls to reach the mobile subscriber, resulting in substantial inconvenience.
Digital wireless cellular and PCS services have implemented integrated voice message and paging systems for mobile subscribers that provide a message waiting indicator on the mobile telephones of the mobile subscribers. Specifically, the digital wireless network includes a mobile telephone switching office (MTSO) for processing wireless calls, and a voicemail system for storing messages by calling parties in the event that the subscriber""s digital mobile phone is in use (i.e., busy), in a standby mode (i.e., turned off), or if there is a no answer condition after a predetermined number of rings.
In particular, a calling party calling a mobile subscriber""s mobile telephone number is connected to the MTSO serving the mobile telephone number. If the MTSO detects a no answer/busy condition for the subscriber""s digital mobile telephone, the MTSO forwards the calling party to the associated voicemail system. The voicemail system plays a personalized greeting established by the subscriber, and records the message.
Once the calling party has recorded the message, the voicemail system sends an instruction to the MTSO to send a message to the digital mobile telephone notifying the mobile subscriber of the voicemail message. If the digital mobile telephone is active, the MTSO sends a page to the digital mobile telephone notifying the subscriber that a call was received. If the digital mobile telephone is inactive (e.g., in standby mode or out of range of the cellular network), the MTSO stores the page until the digital mobile telephone registers with the digital wireless network.
Like the paging system with voice-mail, the above-described cellular systems require a calling party to call a telephone number that is separate from the subscriber""s premises in order to page the subscriber. Hence, a calling party attempting to contact the subscriber at the subscriber""s office may initially only leave a voicemail message at the subscriber""s premises, assuming that the subscriber will reply in a reasonable amount of time. During that time, however, the subscriber away from the office will still be unaware of the stored voicemail message until the calling party either pages the subscriber, or else the subscriber calls into the voicemail system to check for messages.
There is a need for an arrangement that enables subscribers of conventional landline-based voicemail systems configured for receiving transferred incoming calls from telephone switching systems to be notified of messages on the voicemail systems via transmission of notification messages onto a wide area packet switched network. The notification messages can be sent via the wide area packet switched network to a remote destination, such as a mobile telephone.
There is also a need for an arrangement that integrates mobile wireless telephone systems with conventional voicemail systems serving subscribers of conventional telephone switching systems having subscriber telephone lines configured for serving the called party. In particular, there is a need for an arrangement enabling notification of voicemail messages, stored in the subscriber""s voice mailbox based on forwarding information from the telephone switching system, to be automatically supplied to the wireless telephone systems.
There is also a need for arrangement for a voicemail system serving a customer premises that initiates a notification message to a separate wireless telephone system, via an open message transport system, in response to storage of a voicemail message.
There is also a need for an arrangement where a mobile unit subscriber, having a voicemail system for storing personalized voicemail messages based on identity information transferred from a telephone switching system serving the called party on a subscriber telephone line, is automatically paged on the corresponding mobile telephone unit in response to a message stored on the voicemail system.
These and other needs are attained by the present invention, where a voicemail system configured for receiving incoming calls and corresponding forwarding data including subscriber line information for a called party from a telephone switching system, includes a message platform for outputting a notification message onto wide area packet switched network in response to storage of a voicemail message for a voicemail subscriber. The message platform includes a translation table that identifies for each voicemail subscriber whether a notification message should be forwarded to a stored destination address. The destination address identifies a network address of a remote location of the voicemail subscriber. In particular, the destination address may identify a destination wireless telephone network to receive the notification message, plus the destination address of the voicemail subscriber within that destination network.
The voicemail system, upon receiving a transferred call and corresponding forwarding data from a telephone switching system, for example a central office switching system or a private branch exchange, connects the transferred call to a voice message platform configured for storing messages for the voicemail subscriber. The voicemail system also uses the forwarding data to initiate playback of a voicemail prompt in the form of a personalized greeting. The voicemail system generates a notification request in response to storage of a voicemail message in the the voicemail system, enabling the telephone switching system to generate a message waiting indicator at the customer premises, for example on the subscriber""s telephone.
The message platform also detects the notification request for the voicemail subscriber, and checks its internal translation tables to determine whether the voicemail subscriber has enabled a feature for generation of a notification message to a remote destination.
If the voicemail subscriber has enabled generation of the notification message, the message platform formulates a notification message for transmission to a remote destination using a message destination address stored in the translation table that corresponds to the voicemail subscriber. In particular, the notification message may be sent to a wireless digital telephone network, which generates a command to a wireless telephone used by the voicemail subscriber, enabling the voicemail subscriber to be instantly notified from any location in the wireless service area of the new voicemail message.
According to one embodiment of the present invention, the notification message is output as an electronic mail (e-mail) message output onto a packet switched network, such as the Internet, having a message destination address that includes a network address corresponding to an e-mail server of the wireless network. The wireless network, upon receiving the e-mail message, identifies a wireless destination address in the message destination address, and transmits a command to a mobile telephone unit specified by the wireless destination address. The digital telephone, upon receipt of the command, activates a message waiting indicator indicating receipt of a voicemail message at the landline-based voicemail system.
Hence, the present invention provides an arrangement where a voicemail subscriber on a telephone network, such as a public switched telephone network or a corporate network having a private branch exchange, may be remotely notified of new messages stored in his or voice mail box by the transmission of a notification message to a wireless telephone network in communication with a mobile telephone unit used by the voicemail subscriber.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.